1/16/2016
2016 Texas Society of Pathology
Annual Meeting
Well-differentiated
hepatocellular neoplasms
Sanjay Kakar, MD
University of California, San Francisco
Outline
Hepatocellular carcinoma
• Commonly used markers
• Evidence-based panel for diagnosis
Hepatocellular adenoma
• WHO classification
• Distinction from HCC and FNH
Hepatocellular carcinoma
Immunohistochemistry
• Commonly used markers: strengths,
pitfalls
• Choosing a panel
• Clinical scenarios
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Arginase-1
Strengths
Limitations
High sensitivity (90%),
including poorly
differentiated, scirrhous
HCC
Rare positive staining in
other tumors:
-Prostatic
adenocarcinoma
-Cholangiocarcinoma
(weak, focal)
High specificity (>90%):
most other tumors are
negative
Tan, AJSP, 2010; Philips/Kakar, Arch Path Lab Med 2015
Arginase-1: nuclear and/or cytoplasmic
Normal liver
HCC
Hep Par 1
Strengths
Limitations
High sensitivity and
specificity (>80%)
Most adenocarcinomas are
negative
Other mimics of HCC often
negative
Negative: 50% of poorly
differentiated, scirrhous HCC
Focal staining 10-20%
Positive: 20-30% lung,
esophageal, gastric adenoCA
Less common: other tumors
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Hep Par 1 in gastric adenocarcinoma
Glypican-3
Strengths
Limitations
High sensitivity in poorly
differentiated, scirrhous
HCC (>80%)
Negative in adenoma
and most high-grade
dysplastic nodules
Low sensitivity in well
(<50%) and moderately
differentiated HCC
Positive in occasional
cirrhotic nodules, areas
of active hepatitis
Positive in other tumors:
yolk sac, melanoma,
some adenocarcinomas
Baumhoer, Am J Clin Pathol 2008
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GPC-3
Hep Par 1
Shafizadeh/Kakar, Mod Pathol 2009
Glypican-3 in cirrhotic nodule
Polyclonal CEA
Strengths
High sensitivity (>80%)
Canalicular pattern is
specific
Limitations
Negative: 50% of poorly
differentiated, scirrhous
HCC
Can be difficult to
interpret due to
cytoplasmic staining
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HCC
Adenocarcinoma
Sensitivity of commonly used
hepatocellular markers
Well diff
Hep Par 1
pCEA
GPC-3
Arginase-1
100%
92%
62%
100%
Mod diff
Poorly diff
98%
88%
83%
100%
63%
60%
86%
97%
Philips/Kakar, Arch Path Lab Med 2015
Other markers
Marker
AFP
Villin, CD10
TTF-1
CD34
Albumin in situ
hybridization
Limitations
Low sensitivity (30%),
background staining
Similar to polyclonal CEA
Staining similar to Hep Par 1
Clone-dependent
Sinusoidal pattern not specific
Not widely available
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‘Adenocarcinoma’ markers
Marker
Use
MOC31 (EPCAM) Most adenocarcinomas
Neuroendocrine tumors
CK7
HCC: 5-20%
CK19
Pan CK (AE1/AE3) Positive in most HCCs
HCC with MOC31 staining
HCC with CK19 staining
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HCC: immunohistochemistry
Obviously hepatocellular,
benign vs. malignant
HCA, FNH
Dysplastic nodules
Hepatocellular markers not
necessary
Malignant, hepatocellular
vs. other
Cholangiocarcinoma
Metastasis
Angiolipoma
Bile production Mallory hyaline:
no stains
Other situations: ‘mesothelioma
approach’
‘Mesothelioma’ approach
2 hepatocellular
markers
Arginase-1
Glypican-3
Hep Par 1
Polyclonal CEA
2 ‘adenocarcinoma’
markers
MOC31
CK19
CK7
Other markers
Clinical setting
TTF-1,CDX-2,ER/PR,GATA-3
If appropriate
2 marker approach:
Arg-1, CK19
Limited material
Four groups
Group 1
Group 2
Group 3
Group 4
Arginase-1
+
+
-
CK19
+
+
-
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Arginase+ CK19 –
• Establishes the diagnosis of HCC in
most situations
• Additional work-up only if
-clinical info/morphology not typical
-staining pattern focal
Arginase – CK19 +
Differential diagnosis
• Adenocarcinoma
• Polygonal cell tumors:
RCC, NE tumor
• HCC (uncommon)
Arginase+ CK19+
Differential diagnosis
• CK19+ HCC
• Adenocarcinoma/NET with arginase
expression (rare)
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Arginase – CK19 –
Pancytokeratin +
Pancytokeratin -
HCC
Adenocarcinoma
NE tumors, RCC
Urothelial CA
Squamous cell CA
Melanoma
Adrenocortical CA
Angiomyolipoma
Sarcomas with
epithelioid pattern
66/M, 6 cm liver mass
no other known tumor
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Hep Par 1
Hep Par 1
IHC summary
•
•
•
•
•
Hep Par 1 +
Pan CK +
CK7 –
CK20 –
TTF1 –
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Additional stains
Hep Par
+
CK7
-
Arginase-1
-
CK19
+
• HCC (rare)
• Non-HCC with aberrant Hep Par
-Adenocarcinoma
-NET
-Renal cell carcinoma
Chromogranin
Ki-67 index 50%
Diagnosis
Neuroendocrine CA,
large cell, grade 3
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HCC or renal cell carcinoma
Hep Par 1
Hep Par 1
Two-stain approach for clear cell tumors
Arg-1 and PAX-2/PAX-8
Marker
HCC
Clear cell RCC
Arg-1
GPC-3
Hep Par 1
Positive
Negative
PAX-2 or PAX-8
Negative
Positive
RCC marker,
EMA, vimentin
Negative
Positive
CD10
Canalicular
Membranous
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PAX-2 nuclear: metastatic RCC
HCC vs. polygonal cell tumors
Polygonal cell tumor
Marker
Adrenocortical CA
Inhibin
Melan A
Epithelioid
angiomyolipoma
SMA
HMB-45, Melan A
Melanoma
SOX10, S-100
HMB-45, Melan A
Arginase, Hep Par 1: negative
GPC-3: melanoma
55/M with cirrhosis, 6 cm liver mass
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Hep Par, pCEA
MOC31
Atypical features for HCC
• Abundant stroma
• Immunophenotypic features
Negative: Hep Par 1, pCEA
Positive: MOC31
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GPC-3
Hep Par 1
pCEA
CK7
CK19
MOC31
Arginase-1
Glypican-3
CK19
Scirrhous HCC
Conventional HCC
17-20%
33%
58-65%
50%
64%
80-90%
60-80%
0-20%
0-10%
5-11%
95%
95%
95%
70-80%
Matsuura, Histopath, 2005
Krings/Kakar, Mod Pathol 2013
HCC vs. CC
• CC component cannot be diagnosed
based on CK7, CK19 or MOC31 staining
• Strict criteria should be used
Morphology: discrete glands + mucin
IHC: Arg-, CK7/19/MOC31+
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Area 1 (80% of tumor)
Area 1: arginase-1
Area 2 (20% of tumor)
Area 2: CK19
HCC or CC: clinical impact
HCC
Cholangiocarcinoma
Lymph nodes may not be Lymph node dissection is
removed
routine
HCC
Sorafenib, transarterial
chemoembolization
Cholangiocarcinoma
Gemcitabine-based or
fluoropyramidine-based
HCC
Liver transplant:
Milan/UCSF criteria
Cholangiocarcinoma
Likely denial
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Summary
Setting
Approach
Typical morphology
No stains
Initial work-up
2 stain approach:
Arginase-1, MOC31
Most situations in non- 4 stain approach:
cirrhotic liver
Arginase-1, GPC-3/Hep Par 1
CK19, MOC31
• Avoid large reflex staining panels
• Avoid less useful markers like AFP
• Strict criteria for CC component
Outline
Hepatocellular adenoma
• WHO classification
• Diagnosis of histologic subtypes
• Distinction from HCC and FNH
HCA: genetic classification
HNF-1α inactivation
β-catenin activation
IL-6 pathway activated
Mutation-negative
TCF1 gene that encodes
hepatocyte nuclear factor
CTTNB1 exon 3 mutation
(encodes β-catenin
IL6RT gene (encodes
gp130), FRK, STAT3, GNAS
No HNF-1α or β-catenin
mutation
Zucman-Rossi, Hepatology, 2006
WHO blue book, 2010
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HCA subtypes
Women
Steatosis
Cytological
abnormalities
Association
with HCC
Inflammation
Sinusoidal dil
HNF1αmutated
~90%
Common
Rare
β-catenin
mutated
~ 60%
Minority
Common
Inflammatory
Rare
Half
Uncommon
Uncommon
Rare
Minority
Rare
Common
Common
~90%
Minority
5-10%
Bioulac-Sage, Hepatology. 2007
HCA: immunohistochemistry
HNF-1α
mutated
β-catenin
mutated
-Liver fatty acid
binding protein
(LFABP)
-β-catenin
-Glutamine
synthetase (GS)
LFABP negative
Nuclear β-catenin
Diffuse GS
Inflammatory
Unclassified
-C reactive protein (CRP)
No defining
-Serum amyloid associated features
protein (SAA)
CRP+
SAA+
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HNF1α mutated (H-HCA)
• Women
• Steatosis
• Atypia, risk of HCC:
minimal
• Fatty acid binding
protein absent
HCA: genotype-phenotype
HNF1-mutated
Beta-catenin
mutated (exon 3)
Inflammatory
-Fatty acid binding
protein (FABP)
-Beta-catenin
-Glutamine synthetase
(GS)
FABP negative
Nuclear beta-catenin
Diffuse GS
-C reactive protein (CRP)
-Serum amyloid
associated protein (SAA)
CRP+
SAA+
Inflammatory hepatocellular adenoma (I-HCA)
-Inflammation
-Sinusoidal
dilatation
-Ductular
reaction
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SAA in inflammatory adenoma
HCA: immunohistochemistry
HNF-1α
mutated
β-catenin
mutated
-Fatty acid
binding protein
(FABP)
β-catenin
Glutamine
synthetase (GS)
FABP negative
Nuclear β-catenin
Diffuse GS
Inflammatory
-C reactive protein (CRP)
-Serum amyloid associated
protein (SAA)
Unclassified
No defining
features
CRP+
SAA+
β-catenin mutated, exon 3 (b-HCA)
-40% men
-Cytologic atypia, frequent association with HCC
-Nuclear translocation of β-catenin
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Normal liver:
perivenular GS
β-catenin-activated
adenoma: diffuse GS
HCA: WHO classification 2010
HNF-1α
inactivated
Inflammatory
35-50%
Women, OC use
40-50%
Women (OCs), men
Obesity, diabetes
Marked steatosis,
no atypia
HCC rare
LFABP negative
β-catenin
activated
10%
40% in men
Androgens, glycogen
storage disease
Inflammation,
Pseudoacinar, small
sinusoidal dilatation,
cell change
ductular reaction
HCC rare
HCC 40%
SAA positive
Nuclear β-catenin
CRP positive
Diffuse GS
Unclassified (5-10%): no known defining features
H-HCA: diagnostic challenges
Diagnostic challenge
Fat may be absent
Fat in other HCA
subtypes, FNH
LFABP can be weak
LFABP loss in HCC
Approach
Overall morphologic features
LFABP, other stains
Overall morphologic features
LFABP, other stains
Titrate stain appropriately
‘All or none’: any +ve staining usually
means LFABP retained
LFABP is used to subtype HCA
Should not be used to diagnose HCA
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H-HCA without fat
FNH with fat
LFABP loss in HCC
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I-HCA: diagnostic challenges
Diagnostic Challenge
Typical morphology not seen
Morphology like I-HCA, SAA
negative
Approach
10%, SAA and/or CRP positive
SAA negative in 5-10%
Most are CRP-positive
CRP specificity is low
FNH often positive in
periseptal region
SAA, CRP positive in adjacent
liver
I-HCA with diffuse GS
staining
Overlap with FNH
Overall morphologic features
Other stains: SAA, GS
FNH
Focus on morphology
Obtain CD34 stain
10% of cases
Considered as high-risk HCA
Morphology
SAA, CRP, GS
CRP: periseptal staining
I-HCA: diagnostic challenges
Diagnostic Challenge
Approach
Typical morphology not seen
10%, SAA and/or CRP positive
Morphology like I-HCA, SAA
negative
SAA negative in 5-10%
Most are CRP-positive
CRP specificity is low
FNH often positive in periseptal
region
Overall morphologic features
Other stains: SAA, GS
SAA, CRP positive in
adjacent liver
I-HCA with diffuse GS
staining
Overlap with FNH
Focus on morphology
Obtain CD34 stain
10% of cases
Considered as high-risk HCA
Morphology
SAA, CRP, GS
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SAA+ in adjacent liver
GS
SAA
I-HCA: diagnostic challenges
Diagnostic Challenge
Approach
Typical morphology not seen
10%, SAA and/or CRP positive
Morphology like I-HCA, SAA
negative
SAA negative in 5-10%
Most are CRP-positive
CRP specificity is low
FNH often positive in periseptal
region
Overall morphologic features
Other stains: SAA, GS
SAA, CRP positive in adjacent liver
Focus on morphology
Obtain CD34 stain
I-HCA with diffuse GS
staining
Overlap with FNH
10% of cases
Considered as high-risk HCA
Morphology
SAA, CRP, GS
Inflammatory HCA with
β-catenin activation
• 10% of cases
• High risk feature
GS: diffuse
SAA positive
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I-HCA: diagnostic challenges
Diagnostic Challenge
Approach
Typical morphology not seen
10%, SAA and/or CRP positive
Morphology like I-HCA, SAA
negative
SAA negative in 5-10%
Most are CRP-positive
CRP specificity is low
FNH often positive in periseptal
region
Overall morphologic features
Other stains: SAA, GS
SAA, CRP positive in adjacent liver
Focus on morphology
Obtain CD34 stain
I-HCA with diffuse GS staining
10% of cases
Considered as high-risk HCA
Overlap with FNH
Morphology
SAA, CRP, GS
Histologic
feature
FNH
Inflammatory HCA
Fibrous bands
Ductular reaction
Sinusoidal
dilatation
Inflammation
Steatosis
90%
83%
18%
26%
43%
83%
40%
21%
60%
57%
Joseph/Kakar, Mod Pathol 2014
FNH or inflammatory HCA
Immunostain
Inflammatory HCA
FNH
Serum amyloid A
(SAA)
Glutamine
synthetase (GS)
Moderate to strong
Absent/focal
β-catenin activated: diffuse
Others: Perivascular/patchy
Map-like
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GS: map-like pattern
HE stain
SAA+
FNH with map-like GS and SAA+
GS
SAA
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GS: perivascular and patchy staining
GS
FNH with telangiectasia
• Map-like GS pattern
• SAA negative
SAA
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Metastatic adenocarcinoma
Metastatic adenocarcinoma
FNH
FNH: Map-like GS
b-HCA: diagnostic challenges
Diagnostic Challenge
Absence of β-catenin
nuclear staining
Interpretation of GS
staining
Adenoma or HCC
Approach
Low correlation with β-catenin mutation
Diffuse GS staining used as surrogate
Careful attention to patterns
Full significance of different patterns still
under study
Careful review of morphology, reticulin
Strict criteria for HCA and HCC
Use of borderline terminology
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β-catenin: membranous
• Nuclear β-catenin:
often absent in βcatenin mutated cases
• Diffuse GS: Presumed
to have exon 3 βcatenin mutation
GS: diffuse
b-HCA: diagnostic challenges
Diagnostic Challenge
Approach
Absence of β-catenin nuclear Low correlation with β-catenin mutation
staining
Diffuse GS staining used as surrogate
Interpretation of GS
staining
Adenoma or HCC
GS: normal
Careful attention to patterns
Full significance of different patterns
still under study
Careful review of morphology, reticulin
Strict criteria for HCA and HCC
Use of borderline terminology
GS: map-like
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GS patterns in adenoma
Expanded perivascular
Perivascular and patchy
Diffuse
Diffuse homogeneous
GS ~100%
Diffuse heterogeneous
GS >50%
GS: diffuse heterogeneous vs. patchy staining
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GS and β-catenin mutations in HCA
Mutation Patchy
(exon 3)
HCA
HCC
0
15%
Diffuse
50%
17%
Hale/Kakar, USCAP 2014
GS staining patterns
Staining pattern
Diffuse homogeneous
Diffuse heterogeneous
Patchy
Perivascular
Peripheral enhancement
Interpretation
Moderate to strong cytoplasmic staining
90-100% of lesional cells
Likely β-catenin activation
Moderate to strong cytoplasmic staining
in 50-90% of lesional cells
Association with β-catenin activation is
not clear, perhaps in half of the cases
Likelihood of β-catenin activation very
low
b-HCA: diagnostic challenges
Diagnostic Challenge
Approach
Absence of β-catenin nuclear Low correlation with β-catenin mutation
staining
Diffuse GS staining used as surrogate
Interpretation of GS staining
Careful attention to patterns
Full significance of different patterns still under
study
Adenoma or HCC
Careful review of morphology, reticulin
Strict criteria for HCA and HCC
Use of borderline terminology
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HCC: criteria for diagnosis
Two criteria (most cases)
• Cytoarchitectural abnormalities
Small cell change/cytologic atypia
Thick cell plates (at least focally)
Prominent pseudoacinar architecture
• Multifocal reticulin loss
(not necessary if sufficient cytoarchitectural
atypia)
Well-differentiated tumor
Shafizadeh/Kakar, Hum Pathol 2014
Diffuse GS
Nuclear β-catenin
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HCC: reticulin loss
β-catenin activated neoplasm
Adenoma or HCC
Morphology
Atypia: 70%
-Pseudoacinar
-Focally thick
plates
-Focal reticulin
loss
HCC
Other evidence
Concurrent /follow-up: Chromosomal changes
40%
like HCC: 60%
Metastasis: rare cases HSP70+: 50-60%
TERT mutation: ~50%
B Sage, Hepatol 2006
Evason/Kakar, Human Pathol 2012
High risk factors
Focal atypical
Age/gender
morphology
Pseudoacinar Male gender
Small cell
Older age
change
(>50 yrs)
Thick plates
Reticulin loss
Immunostaining
Nuclear β-catenin
Diffuse GS
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Terminology for diagnosis
Biopsy
-High risk features
-Male (any age)
-Women >50 years
Diagnosis
Atypical hepatocellular neoplasm, or
Hepatocellular neoplasm with uncertain
malignant potential (HUMP)
Women, 15-50 years Adenoma
No high risk features
Resection
-Diffuse GS staining
-Focal atypical
features
Diagnosis
Atypical hepatocellular neoplasm, or
Hepatocellular neoplasm with uncertain
malignant potential (HUMP)
Bedossa, Hum Pathol, 2014
Kakar, Hum Pathol, 2014
β-catenin activated hepatocellular
neoplasms
Atypical
HCC
Irrespective of age and Atypical morphology
gender
Irrespective of atypical Multifocal reticulin loss
pathologic features
GPC3 positive
Minimum stains
Stain
Interpretation
Loss:
HCC
Reticulin
Diffuse: Suggest β-catenin activation
GS
SAA
Map-like: FNH
Patchy, no specific pattern: HCA
Inflammatory HCA
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Management of HCA
Management
Tumor characteristics
Conservative with
annual surveillance
Resection
Solitary HCA <5 cm
Women: solitary HCA >5 cm
Men (?women>50 years): all cases
High-risk features
HCA subtypes: US and Europe
Subtype
HNF1α
Inflammatory
β-catenin,
not IHCA
IHCA with
β-catenin
Unclassified
Bioulac-Sage, Shafizadeh/Kakar Thung,
Bioulac-Sage,
Hepatol, 2007 Hum Path 2014
EASL 2013 AJSP 2012
(n=93)
(n=28)
(n=61)
(n=137)
33%
40%
29%
32%
33%
44%
22%
53%
17%
0
2%
2%
2%
3%
2%
11%
8%
36%
16%
13%
Shafizadeh/Kakar, Hum Pathol 2014
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Hepatic adenomatosis
•
•
•
•
By definition, >10 adenomas
Young women
Most are HNF1α-inactivated or inflammatory
Pathogenesis
Obesity, less strong association with OCs
Germline HNF1α mutations
• Glycogen storage disease type I, III
Imaging features
FNH
Central scar
Contrast CT
enhancement
MRI TI-weighted
MRI T2-weighted
Inflammatory
HCA
Present
Early homogenous
Hypointense
Hypointense
Absent
Heterogeneous and
persistent
Hyperintensity
Strong
hyperintensity
FNH vs. IHCA
GS: map-like
SAA: negative
or positive
GS: resembles
map-like, but
not typical
SAA: negative
FNH
Morphology
and imaging
Compatible
with FNH
FNH
Not typical of
FNH
Indeterminate
GS: perivascular
and/or patchy
SAA positive
IHCA
GS: diffuse
SAA: positive
SAA negative
β-catenin
activated
IHCA
Morphology and
imaging
Consider CRP
Likely SAAnegative IHCA
36